Accession Number : AD0810909

Title :   MEASUREMENTS OF SPATIAL COHERENCE IN 3.2-MM HORIZONTAL TRANSMISSION.

Descriptive Note : Rept. for 1 Jul 65-1 Oct 66,

Corporate Author : AEROSPACE CORP EL SEGUNDO CA LABS DIV

Personal Author(s) : Etcheverry, R. D. ; Heidbreder, G. R. ; Johnson, W. A. ; Wintroub, H. J.

Report Date : JAN 1967

Pagination or Media Count : 34

Abstract : An experiment designed to measure wavefront statistics in 3.2-mm wavelength horizontal transmission over an 18.95-km path is described. A frequency-stabilized signal is transmitted over the path and is received in two spaced antennas having variable separation. The receivers are instrumented to measure phase difference and amplitude fluctuations. A simultaneous beam-swinging experiment using a precision-controlled 4.57-m antenna colocated with the phase difference receivers provides data on wavefront tilt fluctuations. Preliminary results indicate that the random wavefront tilt is the predominant atmosphere-induced wavefront phase disturbance. They further suggest that spatial coherence of wavefronts is of sufficient extent that apertures in excess of 7 m in diam are feasible at the 3.2-mm wavelength. (Author)

Descriptors :   (*COHERENT RADIATION, MILLIMETER WAVES), (*WAVE PROPAGATION, MILLIMETER WAVES), PROPAGATION, PHASE MEASUREMENT, PHASE SHIFT CIRCUITS, DIVERSITY RECEPTION, ATMOSPHERES, ATMOSPHERIC MOTION, SCINTILLATION.

Subject Categories : Radiofrequency Wave Propagation

Distribution Statement : APPROVED FOR PUBLIC RELEASE